lumenhours

Lumenhours is a unit of measurement used to quantify the total amount of light energy emitted by a light source over a specific period. It is calculated by multiplying the luminous flux, measured in lumens (lm), by the duration of time the light is on, measured in hours (h). The resulting unit is lumen-hours (lm⋅h). This metric is particularly useful for comparing the overall light output and energy consumption of different lighting solutions when considering their usage duration. For example, a 1000 lumen bulb used for 2 hours would have a lumen-hour value of 2000 lm⋅h. Similarly, a 500 lumen bulb used for 4 hours would also yield 2000 lm⋅h, indicating they provide the same total light energy over their respective operational times. Understanding lumenhours can aid in making informed decisions about lighting efficiency, especially in contexts where lights are used for extended periods. It helps in assessing the cumulative light delivered by a source, which can be relevant for applications such as horticultural lighting, architectural lighting design, or even in the selection of batteries for portable lighting devices. The concept allows for a more holistic view of light performance beyond just instantaneous brightness.